low LE3 383 dyno
low LE3 383 dyno hows it going, obviously I don't post here much (I think this is my 2nd post lol) but frequent this forum alot. I finally managed to get my car dynod this weekend and the results were, well, disappointing to say the least. heres a rundown of what I got done:
Forged 383, 5.7" rods, 16cc dished pistons
LE3 LT1 casting heads with ferrea 2/1.56 valves, comp 977 springs, 55cc chambers, milled slightly, flow .400" 239/165 .600" 272/188 with no pipe on the exhaust. yields approximately 10.7-10.8:1 c/r with the mr gasket .026" thick head gasket.
LE3 camshaft, obviously I can't release the specs but I will say it has a longer duration than a GM847, its on a tighter LSA, and has comparable lift numbers.
Ported LT1 intake that has also been port matched to the head and bored for a 58mm throttle body.
38lb racetronix injectors
Comp 1.6RRs, Comp 'R' lifters (1/16th turn past zero lash)
BBK 58mm tb
mac midlength headers, y-pipe with custom rock induced gouges, 3" in/out carsound high flow cat, and SLP loudmouth catback.
SLP cold air intake
3.73s in a stock rear spinning 315 BFG DRs mounted on 17x11 torque thrust IIs
Built 4L60E with a TCI super street fighter 3500 lock up converter
MadZ28 PCM tune
heres the dyno chart:
http://community.webshots.com/photo/...77515580jnlyZd with bad runs
http://community.webshots.com/photo/...77555806NKXMuv without bad runs
all runs were with the converter unlocked
my known problems before the dyno:
header leak in #1 primary slip tube, gouged Y-pipe, some other leaks that I cant find.
fouled plugs on drivers side caused by the header leak
I noticed my power doesn't drop off much at all. seems to hold 320ish rwhp from 5600 all the way to 6400 then dips down to 300rwhp at 7000. some people suggested a bad fuel pump but would the car still maintain power this high in the rpm range with a faulty fuel pump?
Also suggested was the headers are holding me back some, possibly a clogged cat as well.
Soooo anyone got suggestions on what I can do to get this baby up to where she belongs?
some other stuff:
my previous best track time was a 13.2 @ 104.5 on a high 1.9 60' time. as the night went on I was able to get my 60' down to a high 1.7 which allowed me too hit a 13.4 @ 99! the car got progressively slower each run. I later found out I was getting 8 degrees of knock retard which was causing the car to absolutely die on the top end. I fixed this using the resistor mod. no more knock retard.
The car FEELS much faster now, I know its capable of 12s now. my SOTP dyno says this car is making more than 326 rwhp.
Forged 383, 5.7" rods, 16cc dished pistons
LE3 LT1 casting heads with ferrea 2/1.56 valves, comp 977 springs, 55cc chambers, milled slightly, flow .400" 239/165 .600" 272/188 with no pipe on the exhaust. yields approximately 10.7-10.8:1 c/r with the mr gasket .026" thick head gasket.
LE3 camshaft, obviously I can't release the specs but I will say it has a longer duration than a GM847, its on a tighter LSA, and has comparable lift numbers.
Ported LT1 intake that has also been port matched to the head and bored for a 58mm throttle body.
38lb racetronix injectors
Comp 1.6RRs, Comp 'R' lifters (1/16th turn past zero lash)
BBK 58mm tb
mac midlength headers, y-pipe with custom rock induced gouges, 3" in/out carsound high flow cat, and SLP loudmouth catback.
SLP cold air intake
3.73s in a stock rear spinning 315 BFG DRs mounted on 17x11 torque thrust IIs
Built 4L60E with a TCI super street fighter 3500 lock up converter
MadZ28 PCM tune
heres the dyno chart:
http://community.webshots.com/photo/...77515580jnlyZd with bad runs
http://community.webshots.com/photo/...77555806NKXMuv without bad runs
all runs were with the converter unlocked
my known problems before the dyno:
header leak in #1 primary slip tube, gouged Y-pipe, some other leaks that I cant find.
fouled plugs on drivers side caused by the header leak
I noticed my power doesn't drop off much at all. seems to hold 320ish rwhp from 5600 all the way to 6400 then dips down to 300rwhp at 7000. some people suggested a bad fuel pump but would the car still maintain power this high in the rpm range with a faulty fuel pump?
Also suggested was the headers are holding me back some, possibly a clogged cat as well.
Soooo anyone got suggestions on what I can do to get this baby up to where she belongs?
some other stuff:
my previous best track time was a 13.2 @ 104.5 on a high 1.9 60' time. as the night went on I was able to get my 60' down to a high 1.7 which allowed me too hit a 13.4 @ 99! the car got progressively slower each run. I later found out I was getting 8 degrees of knock retard which was causing the car to absolutely die on the top end. I fixed this using the resistor mod. no more knock retard.
The car FEELS much faster now, I know its capable of 12s now. my SOTP dyno says this car is making more than 326 rwhp.
ohhhh man you need to let that motor breathe i would say get rid of the cat if possible and also look at a set of LT's..... and maybe a dyno tune pending there are no other small probs.... exp fuel pump dying,plugs fouled, header leaks etc
Something is very wrong, maybe your ignition, tune, fuel pump, there are tons of places to look. Lopoked like you were way lean on a few passes. You should be making 65-85 more rwhp. My car put down 341rwhp and 334rwtq with stock heads, moser 12 bolt, and a th350.
Yes, somethign is very wrong.
1st off fix the header leaks and any other exhuast leaks. Any tuner mail order or dyno guy cannot fix a car if its not running mechanically correct.
With that setup you should be doing in the high 300's.
After fixing the leak, check the fuel pressure via a guage attatched to the rail and taped to your wind sheild. Get the FP under load, if it drops at all more than 2 psi, get a new pump. I recommend the racetronix 255lph unit.
Then look at spark, thats another issue.
1) Fuel
2) Air
3) Spark
4) Compression
This is what you need for a healthy motor.
1st off fix the header leaks and any other exhuast leaks. Any tuner mail order or dyno guy cannot fix a car if its not running mechanically correct.
With that setup you should be doing in the high 300's.
After fixing the leak, check the fuel pressure via a guage attatched to the rail and taped to your wind sheild. Get the FP under load, if it drops at all more than 2 psi, get a new pump. I recommend the racetronix 255lph unit.
Then look at spark, thats another issue.
1) Fuel
2) Air
3) Spark
4) Compression
This is what you need for a healthy motor.
Exhaust, go with long tubes, no cats, and an X or H pipe setup, I've heard loud mouth is good at robbing a few ponies. With exhaust alone I bet youll gain 15 to 20 to the ground. Also, ditch the stock fuel pump, it probably isn't feeding the 38lb injectors enough. Check all of your plug wires, shoot each header pipe with a temperature probe after running for just a minute or so, make sure all cylinders are strong. My .02.
